The question to ask is always "If this party or leader (Maduro and his party in this case) was removed from power - by being arrested, or assassinated, or what have you - who would most realistically rush in to fill the power vacuum?" Because it's always easy to be like, oh, yeah, I hate this leader and wish that a communist party took over and led them to the dictatorship of the proletariat, but that's not on the menu much of the time. In Russia for example, Putin and his party's magical removal wouldn't lead to the communist party over there taking over, and even if it did, from what I've seen of it, it doesn't seem especially radical. Same in Iran.

I don't know enough about Venezuela to be able to confidently assert who would rush in, and Venezuela is different from a lot of the countries people do this to because there actually is a communist party of some strength there, but there's at least a very good chance that his replacement would be a reactionary US-friendly comprador, and in comparison to that, Maduro's doing a bang-up job.

In absolute terms, I would say: not great, not terrible. He's a lot easier to support (critically or otherwise) than some of the other leaders we critically support, but not as easy as Cuba or China or the DPRK.